Asker: Gertjan, 19 years old
Answer
It is said to inhale through the nose and exhale through the mouth. The nose actually forms an extra filter. The hairs can stop certain dust particles.
Answered by
Mrs. Céline Christiaens
Molecular biology/biology/chemistry
University of West Flanders
Marksesteenweg 58 B-8500 Kortrijk
http://www.howest.be
Marksesteenweg 58 B-8500 Kortrijk
http://www.howest.be
.